Great looking site Sinhof, a treaure trove in the making and nice cricket bucket too. Yes iron can be a bit tricky on the Deus, especially on the high tone falsing for rusted items, and anything remotely round in shape. With iron, consistancy of the tones and numbers, target sizing, iron grunting on the extremities of the target, and the intensity of the target tone all give clues to a buried iron object.
Round horse tack (metal rings & saddlery) items will give a reasonably sweet tone at depth, though will give an iron tone as the coil is pulled off the target - dig the item up and it will revert to an iron grunt. Most of these items will be identified as iron due to both the intensity of the tone (too good to be true high tone), and pinpointing will usually unveil a larger item at depth, much larger than what you would normally expect for a coin sized target, and jumpy/inconsistent TID's
Best to forget about TID's on the Deus, it is certainly not a CTX and shouldn't be treated as being anywhere as similar - it is a tone based detector and that's where you will find the advantages lay. Only fulltones will give the required information to discern between the good and bad when present with a site full of layered junk. The reason being that with so much ferrous material present, TID's will heavily influenced by nearby iron, and as a result read much lower than what is expected say for example a Victorian penny. That's the point at which you run the discrimination at minimal levels to knock out most iron nails, and let the ears do the discriminating, or as I do, sometimes running with absolutely no discrimination. So essentially you are down to digging either ferrous or non-ferrous rather than trying to pick out say coins via normally expected TID's. Yes you can try and cherry pick the shallower targets via normal TID's on an initial run over the site, though anything deeper and you will most likely walk straight over good targets due to incorrect TID's influenced by surrounding junk.
Probably the worse type of metal to distinguish is not iron, but roofing type iron which is not a pure iron material - this can sound very nice at depth, though irregular shapes can cause the tone and numbers to fluctuate greatly, a coin will offer a more consistent and much smoother tone. Hard to put it in words, though you will know in an instant when you walk over a coin vs other junk, guess it is something that takes a reasonable number of hours on the Deus to become familiarise with such tones.
Worse case scenario is when the ground is so contaminated that a coin no longer sounds anything like what you would expect, the sort of areas where a coin will come out of the ground along with a handfull of rusty nails (ie any old house site). Probably the worse target response I ever had was from a florin, didnt sound anything like a coin netherlone a large silver, it was a real mixed iron/non-ferrous tone (very low for silver), and the cause was several square nails coming from the same hole. I didn't hear silver, though I did get a snippet of non-ferrous, and that was good enough reason to dig. The other thing that gave a clue was during pinpointing, that showed a decent sized target at depth, much more than what you might get from several smaller nail targets. Same can be done for coins or relics sitting alonside much larger iron objects, often the pinpointing will indicate a seperate peak very close to the higher peak of the large iron. I have found many heavily masked items through such methods, whereas many would walk past such targets thinking that they were just falsing from the larger iron object.
It still amuses me on club hunts when detectorists constantly dig up large iron objects due to going off high tones alone, and never bothering to properly size a target through pinpointing. A quick sweep showing a foot wide high tone target is a pretty good indicator to leave the target in the ground.
On the opposite end of the spectrum, some iron targets can turn out to be real interesting artefact or tools from a bygone era - whether you want to find such targets is personal preference. Alternatively it can be seen as ground sterilisation - remove one target to reveal another.
They should have called the Deus the "Scapel", as that's the way I treat it on old house sites - peeling away each layer of junk to unveil masked targets. The more iron you remove, the more targets are revealed. In that sense you can see why old house sites are never totally hunted out, as a fast detector can only find so many targets before its limits are reached, even with the Deus. In theory if you could clear off the first several inches of ferrous laden ground, I'm sure you would end up with a completely revitalised patch of ground again.
One area where the Deus excels is on mid to low conductors, typical items you would find littering a Victorian era site - buttons, jewellery, medallions, thin buckles etc. Especially the case with the newer high frequency coils on which you can get pretty amazing depth on such small & thin targets, not mention revitalised ability for coins sitting on edge.
Stick with it, took me a decent chunk of hours to be comfortable with the Deus, not to mention digging 100's of targets fully understand what the Deus is all about. We have several CTX & Deus users down here who found the transition a bit rocky at first, though most of those guys are now doing really well once they have understood how the two detectors differ and operate, and to which sites they are most suited to.